Process for the manufacture of toluene sulfonic acids.



and .the invention herein describe UNITED STATES PATENT OFFICE.

JOSEPH A. AMIBLEB, 0F NORWICH, CONNECTICUT, .AINII) HARRY D. GIBBS, OFSAN FRANCISCO, CALIFORNIA.

No Drawing.

Specification of Letters Patent.

Patented Jan. 28, 1919.

Application filed January as, 1918. Serial No. 213,978.

(FILED UNDER m ACT 01' MARCH 8, 1888, 22 STAT. In, 69 5.)

To all whom it may concern:

Be it known that we, JOSEPH A. AM'BLER and HARRY D. GIBBS, citizens ofthe United States of America, employees of the Department of Agricultureof the said. United States, residin in the city of Norwich, county ofNew ndon, State of Connecticut and in the city of San Francisco, countyof San Francisco, State of California, respectively, gvhose post-oiliceaddress is Washington, (1,) have jointly invented a new and usefulProcess for the Manufacture of Toluene Sulfonic Acids.

This application is made under the act of March 3, 1883, chapter 143 (22Stat. 625) an claimed may be used by the Government of the UnitedStatesor any of. its oificers or employees in' the prosecution of workfor the Government, or any person in the United States, without paymentto us of any royalt thereon.

eretofore various methods for manufacturing the sulfonic acids oftoluene have been employed, among which are the following:

By adding the toluene to sulfuric *acid or'to sulfuric acid containingsulfur trioxid', under suitable temperature control and with variousmethods of agitation and Eassin the vapors of toluene into a vessel ofea sulfuric acid. 7

(3) By adding sulfuric acid to boiling toluene. a a

It is well known that the product formed when toluene is sulfonateddepends on the temperature of the reaction, the strength of the acid andthe duration of the heating; as, for example, when toluene is sulfonatedat less than 100 'centi ortho and para sul onic acids is obtained;

when toluene is 'sulfonated' at its boiling Q temperature the roduct ismainly para sulfonic acid; whi e at 240 to 250 centigrade, the productis mainly the disulfenie jacid.

3" We have found that'wlien toluene is sulfenated in the dfiaseous stateand the product removed rapi y from the reaction vessel,

fonation. a

much less sulfuric acid-is necessary for sul ade, a mixture of the Weshall illustrate our invention by describing the process for themanufacture of tolueneara-sulfonic acid and toluene-disulfonic acid,although the invention is not restricted to this particular sulfonicacid.

I. Sulfuric acid of specific gravity 1.84 is caused to descend overbathe-plates, pebbles or coarse pumice stones, in a tower, which isheated and maintained at a temperature of 150 centigrade. Toluene isheated to boiling and its vapors are passed up through the tower. Thevapors come into contact with the descending .hot sulfuric acid and arecompletely absorbed by it, with the fcrmation of water and toluenesulfomc acids. The water esca es from the tower as steam and may be conensed in any suitable condenser attached at or near the top of thetower. The sulfonic acids, together with a slight excess of unusedsulfuric acid, are carried downward by means of gravity, and dischargedfrom the bottom of the tower.

II. Sulfuric acid of specific gravity 1.84 is caused to descend overname-plates, pebbles or coarse pumice stones, in a tower, which isheated and maintained at a temperature of 240 to 250 centigrade. Tolueneis heated to boiling and its vapors are passed up' through the tower.The vapors come into contact with the descending hot sulfuric acid andare completely absorbed by it, with the formation of. water and amixture of tol ene-sulfonic acids and toluene disulfonic aci s. Thewater escapes from the tower as steam and may be condensed in anysuitable'condenser attached at or near the top of the tower. Thesulfonic acids, toother with a slight excess of unused sulric acid, arecarried downward by means of gravity, and discharged from the bottom ofthe tower. The products are separated by well known means, and used forthe manufacture of other derivatives of toluene.

, Thus our invention is an improvement on existing methods ofmanufacture of-tcluene sulfonic acids, in that it is a continuousprocess' and the roducts move in a continuous "and automatic mannerandin that less sulabove that at which toluene boils.

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toluene hails, is-de ohstruciions to lbre vapors of toluene to riseratures than 150 oentigre'cle sul 240 to centigrade may be used and ourinvention is not restricted to sue sulfuric acid, temperatures, ortoluene sulfcnic acids, but has a general application to the sulfcnetionof toluene in the aseous state.

Having thus 'd scrihed our claiml. A continuous process for the manufacture of sulfonic acids of toluene b causing the va ors of toluene to mixwith the vapors of sul uric acid.

2. A continuous process for the manufacture of eulfonic cords of toluene:by causing the vapors of toluene to come into contact with a descendingcurrent of sulfuric acid.

3. A continuous process if. the manufacture of sulfonic acids of tolueneby causing the vapors of toluene to come into contact with e descendingounrent cit sulfuric acid, heated and maintained at the temperature atwhich toluene :beiEls.

4.. A continuous process tor the imnufmture of sulfonic acids of tolueneby causing the of toluene to come into contact with e descending currentof sulfuric'a' did, heated and maintained at a temperature invention, we

5. .A continuous s .for the unanuisctmre oi sulfonicectds of toluene bcausing the wepors of-tolaene to rise'tbreug a tower in which at streim'of'suifuric :acid is desoentling ever iehstruotioxfs to break and re-Eor'the manuface. A misuse oti-tfiluflm 11- causing a towertgeoisulimtzr a; t v are. 5 ueneto use I mo in iwhiichn streameif'suliuric sold, and uiaintgihed at the tem e at'which toluene boils.is descendin over obstructions to break retard its all.

7. A ccntinuous process tor the manutiact n-e oi sulienic acids oftoluene causing the vapors of toluene to rise thmug :a tower .m which nstream ofsulfunc and, heated and maintained ata cemperature'above thatat which toluene-boils, 1s .flgiscenclifinuer obstructions tobreak andretard its 8. Acontimuous process 'fpr the menufae tureoftolume-parc-siflf to rise H hich a -s'tmeam oinsullune aclll, heated.undmaintamenl at the. temp p elk nd retard-its: all. 9. A continuousprocess ture of toluene ara-suH for the manufacic acid by causthrough a.tower in which a stream of'sulfuric acid, and maintained at atemperature above --that at. which toluene .boils, is deheated somdinover obstmctiens to break and retard' its all.

10. A continuous process for the manufacture of toluene orthc sulfonicacid by causing the vapors of toluene to rise through a tower in which astream of sulfuric acid, heated and maintained at the temperature atwhich toluene boils, is descendin over obstructions to break and retardits all.

11. A continuous process ture of toluene ortho-sulfonic acid by causingthe vapors of toluene to rise through a .tower in which a stream ofsulfuric acid, heated and maintained at a temperature above that atwhich toluene boils, is descending over obstructions to break andretaird fits fall.

A continuous process for the manufacture of toluene disulfonic acid bcausing the we of toluene to rise through a tower in which .a stream ofsulfuric acid, heated and maintained at a temperature above that atwhich toluene boils, is descending over obstructions to break and retardits .fall.

13. A continuous recess for the manufacture of sulfuric Mi 5 of tolueneb causing the vapors of toluene to rise 't-rcugh a tower in which a.partial vacuum is maintaincd while a stream of sulfuric acid, heated andmaintained at the temperature .at which .toluene boils in :said partialvacuum, is desoendin over obstructions to -break'and retard its all.

' 14. A continuous process for the manuiacture of toluene ortho sulionicacid by causing the vapors of toluene to rise through s. tower inwhach a,partial vacuum is mamt'ained while a stream of sulfuric acid, heatedand Jnaintained at the temperature at which toluene boils in said artialvacuum, isdescendin over obstructions to break '15. A continuous process.factiwe rni toluene ortho-suliomcacid b1 causing the vapors of tolueneto rise throng vawhich apartial vacuum is mainta'medgwh'ile a stream ofsulfuric acid, heated maintained at a; temperature n .at which tomessguons .in said 9 is descendingbver obstruc- :'to break endretard itsiafll.

In'tes'timony whereof, we efixpur s1 atures n. .-fhe presence of twosu'bscr' ing wi, r

for the manu- JOSEPH A. menus. HARRY iD. sinus.

Witnesses:

L. A. Sxnmnn, B. Reunion.

for the manufac-

